's suing. the law signed bygovernorbrownoverthe weekend prohibits licensed mental health professionals from practicing therapies aimed at reversing homosexuality in teenagers. sacramento pacific legal institute filed the suit on behalf of a pastor in san diego who says he benefited from the therapy. the lawsuit claims the law violates free speech. gay rights advocates say the therapy can psychologically harm gay and lesbian youth. >>> they have been preparing for months. and tonight, the presidential candidates are fine-tuning their tactics ahead of their first face-off. tomorrow's debate in denver could help swing the election. cbs 5 political reporter grace lee explains, neither side wants to set the bar too high. >> reporter: that's right, dana. you want to underpromise and overdeliver especially for the first of the three presidential debates. it is considered by most pundits to be the most important because it sets the tone. and for once, both the president and the republican nominee agree on something. they are both trying to lower expectations. the stage is being set at the univ